The goal of this study is to build a better understanding of how widespread COVID-19 is in Canada among our most vulnerable and high-risk populations, as well as the effectiveness and safety of currently approved COVID-19 vaccines:

• We will study the immune response of 2,500 workers and 3,500 residents in long-term care facilities across Ontario, Quebec, and British Columbia and will do vaccine surveillance. 
• Our goal is to gain insight into how various immunity factors, such as antibodies, react to COVID-19 and/or to vaccines. We will compare the immune response in individuals who previously had COVID-19, those who got vaccinated, those who have not been infected, and those who have not been vaccinated. 
• The team will then link the information found from analyzing the blood specimens to participants’ healthcare data to follow individuals over time, including after an infection or after vaccination. 
• We will track the occurrence of adverse events and serious illness over time. More specifically, we will be closely analyzing the subgroup of antibodies, called virus neutralizing antibodies, that protect against new infections.
• The team will also use an app called CANImmunize, which is a pan-Canadian digital immunization tracking application developed by study co-applicant, Dr. Kumanan Wilson. The research team has had the app modified so that long-term care facilities can upload vaccination information for many of their residents and staff at once. This will allow long-term care facilities to track the vaccination records for staff and residents in their facilities. It will also allow each participant to have a record of which vaccine they received, when, and how long it was between their first and second dose.